This invention relates to a combination sofa-sleeper bed and, more particularly, to a sofa of the type which includes a foldable bed having head, body, intermediate and foot sections which may be collapsed and hidden in the bottom of the sofa when the unit is used as a seating surface.
Foldable sofa-sleepers having pivotally interconnected head, body, intermediate and foot sections movable between a fully folded or retracted position within the sofa frame and an extended position wherein the sections extend out and over the front rail of the sofa are known to the art. In general, prior sofa-sleepers of this type have always presented a problem in that a relatively large lifting force is needed to extract the folded bed frame from within the sofa. That is, such prior sofa-sleepers have always required a substantial lifting and forward pulling force to raise the bed frame out from within the sofa until a counterbalance position is reached usually at the point where the main body section has been lifted over the front rail. This relatively large lifting force has made the sleeper unduly cumbersome and difficult to operate. Prior workers in the art have used strong tension springs to aid the operator in extracting the folded bed frame from within the sofa. Such springs however increase the cost and complexity of the unit. Others have modified the support fixture in an attempt to make lifting easier but in so doing have sacrificed lateral stability of the bed in its unfolded or sleeping position. Thus, the head end of the bed tends to sway from side to side in use.
It has therefore been one objective of this invention to provide an improved mechanism for controlling movement of the bed frame between its retracted and extended positions relative to the sofa with a minimum of effort without the necessity of displacing any portion of the sofa framework and without detracting from the lateral stability of the bed. It has been a further objective of this invention to provide a more balanced bed which does not require relatively strong lift springs to operate. These objectives have been accomplished and one aspect of this invention is predicated upon the discovery that a more balanced bed not requiring extremely strong lifting springs to operate may be achieved by a foldable bed frame supporting fixture wherein the forward support lever is pivotally connnected at its lower end to a fixed pivot in an anchor plate mounted to the sofa and the rear support lever is slidable in a generally horizontal slot in the anchor plate from a rearwardmost position when the bed frame is folded within the sofa and a forwardmost position when the bed is fully extended to the sleeping position.
Another disadvantage of many prior art sofa-sleepers has been the problem of "forward shifting" of the sleeper. Forward shifting occurs when the bed frame is in the folded position and nearing the final position as a sofa. Forward shifting causes the bed frame to interfere with the front rail of the sofa. If the shifting is serious enough, it can prevent retraction of the folded bed frame into the sofa.
It has therefore been another objective of this invention to provide a sofa-sleeper fixture which eliminates the problem of forward shifting. This objective has been accomplished by pivotally connecting the upper end of both the front support lever and rear support lever assembly directly to the main body section of the foldable bed frame.
Still another objective of this invention has been to provide an improved linkage for controlling the extension and contraction of the supporting legs of the foot section when the bed is moved from its extended position to its folded position. That is, in many prior art sleepers, the foot section supporting legs do not fully contract when the foot section is folded to a position overlying the body section. Rather, the supporting legs remain slightly lifted with respect to the foot section angles until lifting and rearward thrusting of the frame is begun. At this time, the supporting legs move into engagement with the frame angles of the foot section. If the operator's hands are in the vicinity of the supporting legs, there is a possibility that they can be pinched between the legs and the frame as the bed is folded. This is particularly true where a cross support bar is used to join the legs to improve lateral stability since the cross support bar could be caused to close on the operator's hand in the area where the operator is normally inclined to lift the bed when moving it to its retracted position.
To this end, the sofa-sleeper of this invention incorporates a linkage operable to fully contract the foot section support legs against the bed frame angles by the time the foot section has been fully raised and before folding it over the main body section. Thus, the present invention eliminates the problem of leg lift by fully contracting the legs before the operator begins rearward movement of the bed frame toward the sofa.
Another objective of this invention has been to reduce or eliminate the problem of sheet or blanket pinching. Heretofore, it has been possible for the loose edges of sheets or blankets tucked between the mattress and the bed frame to become pinched between the abutting ends of the four interconnected sections when the bed frame is moved to its extended position thereby cutting the sheets or blankets due to pinching action of the abutting ends. The present invention greatly reduces or eliminates this problem by pivotally interconnecting the bed sections such that their facing ends do not abut in the extended position but rather are spaced one from another so sheets or blankets cannot become pinched therebetween.
In general, the sofa-sleeper fixture of this invention which accomplishes these objectives includes a four section foldable bed frame adapted to be folded into an upholstered stationary box-like sofa frame. The foldable bed frame includes pivotally interconnected head, body, intermediate and foot sections. The pivotally interconnected bed sections are supported in an extended bed position by a plurality of foldable legs and by forward and rear support levers pivotally connected at their upper ends directly to the main body section of the frame with the forward lever being pivotally connected at its lower end to a fixed pivot in an anchor plate secured to the sofa side frame and the rear support lever at its base being slidable within a generally horizontal slot within the anchor plate between a rearwardmost position when the bed is fully retracted and a forwardmost position when the bed is fully extended. Interconnected linkages are operable to automatically retract the legs into a folded position when the bed frame is folded into a sofa position. The legs supporting the foot section of the bed frame are extended and retracted by means of actuating arms, each connected at one end to the leg and at the other end to a bell crank pivotally connected to the intermediate section. This linkage is operable to automatically lock the foot support legs to the frame when the foot section is raised just past a vertical position prior to being folded over the body section and well prior to rearward movement of the partially folded sections toward the sofa.
A primary advantage of the combination sofa-sleeper of this application is its improved balance which eliminates the requirements for strong lift springs to aid in extracting the folded bed frame from within the sofa frame while at no sacrifice to the lateral stability of the bed. A further advantage of this invention is its adaptability to styles and shapes of upholstered sofa constructions which have different seating height surfaces or which have differing thicknesses of mattresses. This ability to accommodate different heights and different mattresses enables a single fixture to fit numerous styles and variations of sofa sleepers.
Further advantages of this sofa-sleeper reside in the comfort of its seating and sleeping surfaces and the elimination or at least substantial reduction of the tendency of the bed frame to pinch and cause tearing of sheets and blankets.
In its general aspect, the combination of this invention provides a better balanced sofa-sleeper which is easier to manufacture with less weight and at lower cost.
These and other objects and advantages of this invention will be more readily apparent from the following detailed description of the invention taken with the accompanying drawings.